I'm working on the simulation of a chemical process at lab scale, this process consists of putting reagents in an autoclave reactor and putting it in an oven .The problem is that the reactions ,kinetics and thermodynamics inside the reactor are unknown. Thanks in advance
Dear Mouad,
in a first approach you could try to measure the heat balance of your reactor. The thermal conversion equals the chemical conversion.
For calculating the heat balance you should perform one experiment observing the temperature inside the reactor without reagents (to determine the heat capacity of your reactor). In a second experiment you should observe the temperature profile inside the reactor with the chemical reaction going on (to determine the reaction enthalpy).
Best,
Sascha
You could try to measure
1 the heat balance
2 the mass balance
3 time t
4 analysis (before/after experiments)
...see links below (Russian, but you can use google translate, for example :) )
Article Stochastic Modeling and Optimization of the Precipitation Ce...
Presentation 1_3_Lecture_Modeling algorithm_Моделирующий алгоритм
Presentation 1_2_Lecture_Types of modeling_Виды моделирования
Presentation 1_1_Lecture_Mathematical models_Математические модели
You cannot. The essence of simulation is to predict a process kinetic or dynamic from heat, mass or momentum balances knowing physical properties, thermodynamic properties, transport properties and/or hydrodynamic properties. Now, Prof. Nehr has reason if you have not information you can developed experiments for recollect information that you could use for properties estimation and a posterior simulation. I assume that you know which reagents are used, their physical state (solid, liquid or gas), their density, their heat capacity, their vapor pressure (if they are solids or liquids and therefore the boiling temperature at autoclave pressure); you must know the mass of reagents feed. Then the experiments suggested by Prof. Nehr will help to you to identify what´s happen inside reactor. I only add that you must measure the pressure history inside reactor and the temperature inside reagent mixture if they are in liquid phase. The temperature and pressure behavior during reaction will indicate to you if some type of chemical reaction occurs. You can simulate the temperature of reagent mixture from the energy supplied to reactor and the heat capacity of mixture elements. Deviations from this behavior will indicate exothermal or endothermal reaction. Irregularities in pressure will indicate new components in gas phase formation.
Thank you all for your answers ,I really appreciate them
best regards
You need to identify the products and discover how much of reactants are remaining after different reaction times. Then guess at a mechanism and plot the data to test the guess. Reaction must be stopped before completion to get data for testing mechanisms.
If you know the inputs, the outputs and some recorded parameter such as temperature, etc.. you could try a neural network model. tipically a machine learning approach
Simulation of what - the reactor (as you wrote) or the chemical process in the reactor (as one can guess). How - experimentally (small scale experiment) or theoretically. In the first case you do not need thermodynamic and kinetic data, but in the second case yes. The problem, however, is that in order to get them you need to carry out properly scheduled experiments. So start with stoichiometry. Thus a system of linearly independent stoichiometric equations and, on the basis of which, the key reagents whose concentration you need to measure. Experiment, preferably under isothermal conditions. And then the quantitative description of the results - that is the equations of mass balance and the assumed form of kinetic equations. You will also need the thermodynamic data - the equilibrium constant for reversible reactions and reactions heat in the case of process simulation under non-isothermal conditions
A lot of work ahead of you.
Regards,
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